This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Examine the behavioral effects of 26 hours total sleep deprivation and 6 nights partial sleep deprivation on specific components of decision making. Examine the cerebral effects of total sleep deprivation and partial sleep deprivation on specific components of decision making.